Taking Out Concrete Slabs in South Florida and Keeping the Rubble Out of the Landfill

Concrete is everywhere in Miami: slab-on-grade homes, block walls, driveways, warehouse floors and tilt-up panels. When a property is redeveloped, that material has to go somewhere. In many cases a good portion can be crushed and reused as aggregate instead of buried. This article describes the general process and the decisions that matter. Hauling and recycling options change, so check with your contractor about what is available for your project.

Where you meet slab-heavy jobs

Large warehouse floors and panelized buildings are common in the Doral and Miami International Airport corridor, and former industrial blocks in Wynwood often involve thick slabs as well. Smaller infill lots in Little Havana usually have a house slab, a driveway and a few retaining walls. Scale changes the equipment, not the basic steps.

The usual workflow

• Survey and plan: Identify the slab thickness, any post-tension cables, reinforcing, and what sits under it, such as old tanks, drains or utility lines.
• Saw cut where needed: For partial removal, saw cutting makes a clean edge and protects the slab that stays.
• Break and size: Excavators with hydraulic breakers or crushers fracture slabs and footings into pieces that can be handled and loaded.
• Separate steel: Rebar and mesh are pulled out. Metal is generally sold for recycling, and cleaner concrete is easier to process.
• Haul to a permitted facility: Concrete typically goes to a permitted construction and demolition debris or recycling facility. Your contractor can explain which is practical for your location.

South Florida wrinkles

• Salt air and moisture: Near the coast, rebar can corrode and cause spalling, which may change how brittle or contaminated the concrete is. It can also affect whether the material is suitable for reuse.
• Limestone below: The rock layer under much of Miami-Dade, along with shallow groundwater, affects how deep you can dig and how much you can expect to move after the slab is up.
• Dust and noise: Crushing and breaking in a dense neighborhood calls for water for dust control and attention to working hours set by the local jurisdiction.

What you can do to help

Keep wood, garbage and other non-concrete material out of the concrete pile, since contamination can send an otherwise recyclable load to a different destination. Mark any slab you want to preserve and tell the crew about buried items you know about. Finally, check that the permit, asbestos and Sunshine 811 steps are finished before the first break.